Selecting Appliances

Jan 30, 2014

The appliances you
select for the deployment must
all be the same model, running the same software version. Otherwise, management
and troubleshooting can become impractical.

Your appliance
choice is generally made by comparing your site’s WAN bandwidth and number of
WAN users to the capacities of the different appliances in the
CloudBridge Data
Sheet. For fault tolerance, always order one more appliance than is
absolutely required according to the data sheet.

The number of
appliances you need is found as follows, rounding up all fractions:

Note that if
appliances = 2, you can use just a single appliance instead of WCCP clustering,
or an HA pair instead of WCCP clustering, since the equation builds in a spare
appliance. In other words, WCCP clustering is not necessary (from a capacity
perspective) unless appliances is 3 or more.

Example. Suppose you
have 700 users and a 100 Mbps link. Some appliances you might consider are the
CloudBridge 2000-050, the CloudBridge 3000-100, and the CloudBridge 4000-310.

Model

Optimized WAN Capacity

Maximum
HDX Sessions

Appliances_bw

Appliances_users

Appliances

2000-050

50 Mbps

300

3

4

4

3000-100

100
Mbps

400

2

3

3

4000-310

310
Mbps

750

2

2

2

As you can see from
the above table, the higher-performance platforms require fewer appliances to
get the job done, as you would expect. The CloudBridge 4000-310 meets the
requirements with a single appliance, and evaluates to two appliances only
because the equations build in a spare.

You can always add
more capacity by adding more appliances, but that is not always necessary. The
bandwidth limits of two of the three choices, the CloudBridge 3000-100 and the
CloudBridge 4000-310, can be increased through a license upgrade. The
CloudBridge 2000-050 however, is already at the high end of the range for
CloudBridge 2000 appliances.